<template>
  <div class="home-page">
    <div class="banner">
      <div class="container">
        <h1 class="logo-font">conduit</h1>
        <p>A place to share your knowledge.</p>
      </div>
    </div>

    <div class="container page">
      <div class="row">
        <div class="col-md-9">
          <div class="feed-toggle">
            <ul class="nav nav-pills outline-active">
              <li v-if="user" class="nav-item">
                <nuxt-link
                  class="nav-link"
                  :class="{active: tab === 'your_feed'}"
                  exact
                  :to="{
                    name: 'home', 
                    query: {
                      tab: 'your_feed'
                      }
                    }"
                >Your Feed</nuxt-link>
              </li>
              <li class="nav-item">
                <nuxt-link
                  class="nav-link"
                  :class="{active: tab === 'global_feed'}"
                  exact
                  :to="{name: 'home', query: {tab: 'global_feed'}}"
                >Global Feed</nuxt-link>
              </li>
              <li v-if="tag" class="nav-item">
                <nuxt-link
                  class="nav-link"
                  :class="{active: tab === 'tag'}"
                  exact
                  :to="{name: 'home', query: {tab: 'tag', tag: tag}}"
                ># {{tag}}</nuxt-link>
              </li>
            </ul>
          </div>

          <div class="article-preview" v-for="article in articles" :key="article.slug">
            <div class="article-meta">
              <nuxt-link
                :to="{
                name: 'profile',
                params: {
                  username: article.author.username
                }
              }"
              >
                <img :src="article.author.image" />
              </nuxt-link>
              <div class="info">
                <nuxt-link
                  :to="{
                    name: 'profile',
                    params: {
                      username: article.author.username
                    }
                  }"
                >{{ article.author.username }}</nuxt-link>

                <span class="date">{{article.createdAt | date('MMM DD, YYYY')}}</span>
              </div>
              <button
                class="btn btn-outline-primary btn-sm pull-xs-right"
                :class="{
                  active: article.favorited
                }"
                :disabled="article.favoriteDisabled"
                @click="onFavorite(article)"
              >
                <i class="ion-heart"></i>
                {{article.favoritesCount}}
              </button>
            </div>
            <nuxt-link
              :to="{
                name: 'article',
                params: {
                  slug: article.slug
                }
              }"
              class="preview-link"
            >
              <h1>{{ article.title }}</h1>
              <p>{{ article.description }}</p>
              <span>Read more...</span>
            </nuxt-link>
          </div>
          <div class="article-preview" v-if="articles.length === 0">No articles are here... yet.</div>
        </div>
        <nav>
          <ul class="pagination">
            <li
              class="page-item"
              :class="{
                active: page === item
              }"
              v-for="item in totalPage"
              :key="item"
            >
              <nuxt-link
                class="page-link"
                :to="{
                name: 'home',
                query: {
                  page: item,
                  //tag: $route.query.tag,
                  tab: tab,
                  tag: tag
                }
                }"
              >{{item}}</nuxt-link>
            </li>
          </ul>
        </nav>
        <div class="col-md-3">
          <div class="sidebar">
            <p>Popular Tags</p>

            <div class="tag-list">
              <nuxt-link
                class="tag-pill tag-default"
                v-for="tag in tags"
                :key="tag"
                :to="{
                  name:'home',
                  query: {
                    tag: tag,
                    tab: 'tag'
                  }
                }"
              >{{tag}}</nuxt-link>
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import { getArticles, getYourFeedArticles, addFavorite, deleteFavorite } from "@/api/article"
import { getTags } from "@/api/tag"
import { mapState } from 'vuex'

export default {
  name: 'HomeIndex',
  async asyncData({ query }) {
    const page = Number.parseInt(query.page || 1)
    const limit = 20
    const tab = query.tab || 'global_feed'
    const tag = query.tag
    const loadArticles = tab === 'your_feed' ? getYourFeedArticles : getArticles
    const [articleRes, tagRes] = await Promise.all([
      loadArticles({
        limit,
        offset: (page - 1) * limit,
        tag
      }),
      getTags()
    ])

    const { articles, articlesCount } = articleRes.data
    const { tags } = tagRes.data

    articles.forEach(article => article.favoriteDisabled = false)
    return {
      articles,
      articlesCount,
      tags,
      tab,
      tag,
      limit,
      page
    }
  },
  watchQuery: ['page', 'tag', 'tab'],
  computed: {
    ...mapState(['user']),
    totalPage() {
      return Math.ceil(this.articlesCount / this.limit)
    }
  },
  methods: {
    async onFavorite(article) {
      if(!this.user){
        return this.$router.push('/login')
      }
      article.favoriteDisabled = true
      if (article.favorited) {
        await deleteFavorite(article.slug)
        article.favorited = false
        article.favoritesCount += -1
      } else {
        await addFavorite(article.slug)
        article.favorited = true
        article.favoritesCount += 1
      }
      article.favoriteDisabled = false
    }
  }
}
</script>

<style>
</style>